test/loops/NavigableSetCheck.java

/*
 * Written by Doug Lea with assistance from members of JCP JSR-166
 * Expert Group and released to the public domain, as explained at
 * http://creativecommons.org/publicdomain/zero/1.0/
 */
/**
 * @test
 * @synopsis Times and checks basic set operations
 */
import java.io.*;
import java.util.*;

public class NavigableSetCheck {

    static int absentSize;
    static int absentMask;
    static Integer[] absent;

    static final Integer MISSING = new Integer(Integer.MIN_VALUE);

    static TestTimer timer = new TestTimer();

    static void reallyAssert(boolean b) {
        if (!b) throw new Error("Failed Assertion");
    }

    public static void main(String[] args) throws Exception {
        Class<?> setClass = null;
        int numTests = 50;
        int size = 50000;

        if (args.length > 0) {
            try {
                setClass = Class.forName(args[0]);
            } catch (ClassNotFoundException e) {
                throw new RuntimeException("Class " + args[0] + " not found.");
            }
        }

        if (args.length > 1)
            numTests = Integer.parseInt(args[1]);

        if (args.length > 2)
            size = Integer.parseInt(args[2]);

        System.out.println("Testing " + setClass.getName() + " trials: " + numTests + " size: " + size);

        absentSize = 8;
        while (absentSize < size) absentSize <<= 1;
        absentMask = absentSize - 1;
        absent = new Integer[absentSize];

        for (int i = 0; i < absentSize; ++i)
            absent[i] = new Integer(i * 2);

        Integer[] key = new Integer[size];
        for (int i = 0; i < size; ++i)
            key[i] = new Integer(i * 2 + 1);

        for (int rep = 0; rep < numTests; ++rep) {
            runTest(newSet(setClass), key);
        }

        TestTimer.printStats();
    }

    static NavigableSet newSet(Class<?> cl) {
        try {
            NavigableSet m = (NavigableSet) cl.newInstance();
            return m;
        } catch (Exception e) {
            throw new RuntimeException("Can't instantiate " + cl + ": " + e);
        }
    }

    static void runTest(NavigableSet s, Integer[] key) {
        shuffle(key);
        int size = key.length;
        long startTime = System.currentTimeMillis();
        test(s, key);
        long time = System.currentTimeMillis() - startTime;
    }

    static void t1(String nm, int n, NavigableSet s, Integer[] key, int expect) {
        int sum = 0;
        int iters = 4;
        timer.start(nm, n * iters);
        for (int j = 0; j < iters; ++j) {
            for (int i = 0; i < n; i++) {
                if (s.contains(key[i])) ++sum;
            }
        }
        timer.finish();
        reallyAssert(sum == expect * iters);
    }

    static void t2(String nm, int n, NavigableSet s, Integer[] key, int expect) {
        int sum = 0;
        timer.start(nm, n);
        for (int i = 0; i < n; i++) {
            if (s.remove(key[i])) ++sum;
        }
        timer.finish();
        reallyAssert(sum == expect);
    }

    static void t3(String nm, int n, NavigableSet s, Integer[] key, int expect) {
        int sum = 0;
        timer.start(nm, n);
        for (int i = 0; i < n; i++) {
            if (s.add(key[i])) ++sum;
        }
        timer.finish();
        reallyAssert(sum == expect);
    }

    static void t4(String nm, int n, NavigableSet s, Integer[] key, int expect) {
        int sum = 0;
        timer.start(nm, n);
        for (int i = 0; i < n; i++) {
            if (s.contains(key[i])) ++sum;
        }
        timer.finish();
        reallyAssert(sum == expect);
    }

    static void t5(String nm, int n, NavigableSet s, Integer[] key, int expect) {
        int sum = 0;
        timer.start(nm, n/2);
        for (int i = n-2; i >= 0; i-=2) {
            if (s.remove(key[i])) ++sum;
        }
        timer.finish();
        reallyAssert(sum == expect);
    }

    static void t6(String nm, int n, NavigableSet s, Integer[] k1, Integer[] k2) {
        int sum = 0;
        timer.start(nm, n * 2);
        for (int i = 0; i < n; i++) {
            if (s.contains(k1[i])) ++sum;
            if (s.contains(k2[i & absentMask])) ++sum;
        }
        timer.finish();
        reallyAssert(sum == n);
    }

    static void t7(String nm, int n, NavigableSet s, Integer[] k1, Integer[] k2) {
        int sum = 0;
        timer.start(nm, n * 2);
        for (int i = 0; i < n; i++) {
            if (s.contains(k1[i])) ++sum;
            if (s.contains(k2[i & absentMask])) ++sum;
        }
        timer.finish();
        reallyAssert(sum == n);
    }

    static void t8(String nm, int n, NavigableSet s, Integer[] key, int expect) {
        int sum = 0;
        timer.start(nm, n);
        for (int i = 0; i < n; i++) {
            if (s.contains(key[i])) ++sum;
        }
        timer.finish();
        reallyAssert(sum == expect);
    }

    static void higherTest(NavigableSet s) {
        int sum = 0;
        int iters = s.size();
        timer.start("Higher                 ", iters);
        Object e = s.first();
        while (e != null) {
            ++sum;
            e = s.higher(e);
        }
        timer.finish();
        reallyAssert(sum == iters);
    }

    static void lowerTest(NavigableSet s) {
        int sum = 0;
        int iters = s.size();
        timer.start("Lower                  ", iters);
        Object e = s.first();
        while (e != null) {
            ++sum;
            e = s.higher(e);
        }
        timer.finish();
        reallyAssert(sum == iters);
    }

    static void ceilingTest(NavigableSet s) {
        int sum = 0;
        int iters = s.size();
        if (iters > absentSize) iters = absentSize;
        timer.start("Ceiling                ", iters);
        for (int i = 0; i < iters; ++i) {
            Object e = s.ceiling(absent[i]);
            if (e != null)
                ++sum;
        }
        timer.finish();
        reallyAssert(sum == iters);
    }

    static void floorTest(NavigableSet s) {
        int sum = 0;
        int iters = s.size();
        if (iters > absentSize) iters = absentSize;
        timer.start("Floor                  ", iters);
        for (int i = 1; i < iters; ++i) {
            Object e = s.floor(absent[i]);
            if (e != null)
                ++sum;
        }
        timer.finish();
        reallyAssert(sum == iters-1);
    }

    static void ktest(NavigableSet s, int size, Integer[] key) {
        timer.start("Contains               ", size);
        int sum = 0;
        for (int i = 0; i < size; i++) {
            if (s.contains(key[i])) ++sum;
        }
        timer.finish();
        reallyAssert(sum == size);
    }

    static void ittest1(NavigableSet s, int size) {
        int sum = 0;
        timer.start("Iter Key               ", size);
        for (Iterator it = s.iterator(); it.hasNext(); ) {
            if (it.next() != MISSING)
                ++sum;
        }
        timer.finish();
        reallyAssert(sum == size);
    }

    static void ittest(NavigableSet s, int size) {
        ittest1(s, size);
    }

    static void rittest1(NavigableSet s, int size) {
        int sum = 0;
        timer.start("Desc Iter Key          ", size);
        for (Iterator it = s.descendingIterator(); it.hasNext(); ) {
            if (it.next() != MISSING)
                ++sum;
        }
        timer.finish();
        reallyAssert(sum == size);
    }

    static void rittest(NavigableSet s, int size) {
        rittest1(s, size);
    }

    static void rtest(NavigableSet s, int size) {
        timer.start("Remove (iterator)      ", size);
        for (Iterator it = s.iterator(); it.hasNext(); ) {
            it.next();
            it.remove();
        }
        timer.finish();
    }

    static void dtest(NavigableSet s, int size, Integer[] key) {
        timer.start("Add (addAll)           ", size * 2);
        NavigableSet s2 = null;
        try {
            s2 = (NavigableSet) (s.getClass().newInstance());
            s2.addAll(s);
        }
        catch (Exception e) { e.printStackTrace(); return; }
        timer.finish();

        timer.start("Iter Equals            ", size * 2);
        boolean eqt = s2.equals(s) && s.equals(s2);
        reallyAssert(eqt);
        timer.finish();

        timer.start("Iter HashCode          ", size * 2);
        int shc = s.hashCode();
        int s2hc = s2.hashCode();
        reallyAssert(shc == s2hc);
        timer.finish();

        timer.start("Add (present)          ", size);
        s2.addAll(s);
        timer.finish();

        t6("Contains               ", size, s2, key, absent);

        boolean as2 = s2.add(absent[absentSize-1]);
        reallyAssert(as2);
        timer.start("Iter Equals            ", size * 2);
        eqt = s2.equals(s) && s.equals(s2);
        if (as2)
            reallyAssert(!eqt);
        timer.finish();

        timer.start("Iter HashCode          ", size * 2);
        int s1h = s.hashCode();
        int s2h = s2.hashCode();
        if (as2)
            reallyAssert(s1h != s2h);
        timer.finish();

        timer.start("Clear                  ", size);
        s.clear();
        s2.clear();
        timer.finish();
        reallyAssert(s2.isEmpty() && s.isEmpty());
    }

    static void test(NavigableSet s, Integer[] key) {
        int size = key.length;

        t3("Add (absent)           ", size, s, key, size);
        t3("Add (present)          ", size, s, key, 0);
        t7("ContainsKey            ", size, s, key, absent);
        t4("ContainsKey            ", size, s, key, size);
        ktest(s, size, key);
        t4("Contains               ", absentSize, s, absent, 0);
        t6("Contains               ", size, s, key, absent);
        t1("Contains (present)     ", size, s, key, size);
        t1("Contains (absent)      ", absentSize, s, absent, 0);
        t2("Remove (absent)        ", absentSize, s, absent, 0);
        t5("Remove (present)       ", size, s, key, size / 2);
        t3("Add (half present)     ", size, s, key, size / 2);

        ittest(s, size);
        rittest(s, size);
        higherTest(s);
        ceilingTest(s);
        floorTest(s);
        lowerTest(s);
        rtest(s, size);

        t4("Contains               ", size, s, key, 0);
        t2("Remove (absent)        ", size, s, key, 0);
        t3("Add (presized)         ", size, s, key, size);
        dtest(s, size, key);
    }

    static class TestTimer {
        private String name;
        private long numOps;
        private long startTime;
        private String cname;

        static final java.util.TreeMap accum = new java.util.TreeMap();

        static void printStats() {
            for (Iterator it = accum.entrySet().iterator(); it.hasNext(); ) {
                Map.Entry e = (Map.Entry) it.next();
                Stats stats = (Stats) e.getValue();
                int n = stats.number;
                double t;
                if (n > 0)
                    t = stats.sum / n;
                else
                    t = stats.least;
                long nano = Math.round(1000000.0 * t);
                System.out.println(e.getKey() + ": " + nano);
            }
        }

        void start(String name, long numOps) {
            this.name = name;
            this.cname = classify();
            this.numOps = numOps;
            startTime = System.currentTimeMillis();
        }

        String classify() {
            if (name.startsWith("Contains"))
                return "Contains               ";
            else if (name.startsWith("Add"))
                return "Add                    ";
            else if (name.startsWith("Remove"))
                return "Remove                 ";
            else if (name.startsWith("Iter"))
                return "Iter                   ";
            else
                return null;
        }

        void finish() {
            long endTime = System.currentTimeMillis();
            long time = endTime - startTime;
            double timePerOp = (double) time / numOps;

            Object st = accum.get(name);
            if (st == null)
                accum.put(name, new Stats(timePerOp));
            else {
                Stats stats = (Stats) st;
                stats.sum += timePerOp;
                stats.number++;
                if (timePerOp < stats.least) stats.least = timePerOp;
            }

            if (cname != null) {
                st = accum.get(cname);
                if (st == null)
                    accum.put(cname, new Stats(timePerOp));
                else {
                    Stats stats = (Stats) st;
                    stats.sum += timePerOp;
                    stats.number++;
                    if (timePerOp < stats.least) stats.least = timePerOp;
                }
            }

        }

    }

    static class Stats {
        double sum = 0;
        double least;
        int number = 0;
        Stats(double t) { least = t; }
    }

    static Random rng = new Random();

    static void shuffle(Integer[] keys) {
        int size = keys.length;
        for (int i = size; i > 1; i--) {
            int r = rng.nextInt(i);
            Integer t = keys[i-1];
            keys[i-1] = keys[r];
            keys[r] = t;
        }
    }

}
Revision:	1.13
Committed:	Mon Aug 10 03:13:33 2015 UTC (8 years, 9 months ago) by jsr166
Branch:	MAIN
Changes since 1.12:	+0 -1 lines
Log Message:	delete unwanted blank lines
#	Content
1	/*
2	* Written by Doug Lea with assistance from members of JCP JSR-166
3	* Expert Group and released to the public domain, as explained at
4	* http://creativecommons.org/publicdomain/zero/1.0/
5	*/
6	/**
7	* @test
8	* @synopsis Times and checks basic set operations
9	*/
10	import java.io.*;
11	import java.util.*;
12
13	public class NavigableSetCheck {
14
15	static int absentSize;
16	static int absentMask;
17	static Integer[] absent;
18
19	static final Integer MISSING = new Integer(Integer.MIN_VALUE);
20
21	static TestTimer timer = new TestTimer();
22
23	static void reallyAssert(boolean b) {
24	if (!b) throw new Error("Failed Assertion");
25	}
26
27	public static void main(String[] args) throws Exception {
28	Class<?> setClass = null;
29	int numTests = 50;
30	int size = 50000;
31
32	if (args.length > 0) {
33	try {
34	setClass = Class.forName(args[0]);
35	} catch (ClassNotFoundException e) {
36	throw new RuntimeException("Class " + args[0] + " not found.");
37	}
38	}
39
40	if (args.length > 1)
41	numTests = Integer.parseInt(args[1]);
42
43	if (args.length > 2)
44	size = Integer.parseInt(args[2]);
45
46	System.out.println("Testing " + setClass.getName() + " trials: " + numTests + " size: " + size);
47
48	absentSize = 8;
49	while (absentSize < size) absentSize <<= 1;
50	absentMask = absentSize - 1;
51	absent = new Integer[absentSize];
52
53	for (int i = 0; i < absentSize; ++i)
54	absent[i] = new Integer(i * 2);
55
56	Integer[] key = new Integer[size];
57	for (int i = 0; i < size; ++i)
58	key[i] = new Integer(i * 2 + 1);
59
60	for (int rep = 0; rep < numTests; ++rep) {
61	runTest(newSet(setClass), key);
62	}
63
64	TestTimer.printStats();
65	}
66
67	static NavigableSet newSet(Class<?> cl) {
68	try {
69	NavigableSet m = (NavigableSet) cl.newInstance();
70	return m;
71	} catch (Exception e) {
72	throw new RuntimeException("Can't instantiate " + cl + ": " + e);
73	}
74	}
75
76	static void runTest(NavigableSet s, Integer[] key) {
77	shuffle(key);
78	int size = key.length;
79	long startTime = System.currentTimeMillis();
80	test(s, key);
81	long time = System.currentTimeMillis() - startTime;
82	}
83
84	static void t1(String nm, int n, NavigableSet s, Integer[] key, int expect) {
85	int sum = 0;
86	int iters = 4;
87	timer.start(nm, n * iters);
88	for (int j = 0; j < iters; ++j) {
89	for (int i = 0; i < n; i++) {
90	if (s.contains(key[i])) ++sum;
91	}
92	}
93	timer.finish();
94	reallyAssert(sum == expect * iters);
95	}
96
97	static void t2(String nm, int n, NavigableSet s, Integer[] key, int expect) {
98	int sum = 0;
99	timer.start(nm, n);
100	for (int i = 0; i < n; i++) {
101	if (s.remove(key[i])) ++sum;
102	}
103	timer.finish();
104	reallyAssert(sum == expect);
105	}
106
107	static void t3(String nm, int n, NavigableSet s, Integer[] key, int expect) {
108	int sum = 0;
109	timer.start(nm, n);
110	for (int i = 0; i < n; i++) {
111	if (s.add(key[i])) ++sum;
112	}
113	timer.finish();
114	reallyAssert(sum == expect);
115	}
116
117	static void t4(String nm, int n, NavigableSet s, Integer[] key, int expect) {
118	int sum = 0;
119	timer.start(nm, n);
120	for (int i = 0; i < n; i++) {
121	if (s.contains(key[i])) ++sum;
122	}
123	timer.finish();
124	reallyAssert(sum == expect);
125	}
126
127	static void t5(String nm, int n, NavigableSet s, Integer[] key, int expect) {
128	int sum = 0;
129	timer.start(nm, n/2);
130	for (int i = n-2; i >= 0; i-=2) {
131	if (s.remove(key[i])) ++sum;
132	}
133	timer.finish();
134	reallyAssert(sum == expect);
135	}
136
137	static void t6(String nm, int n, NavigableSet s, Integer[] k1, Integer[] k2) {
138	int sum = 0;
139	timer.start(nm, n * 2);
140	for (int i = 0; i < n; i++) {
141	if (s.contains(k1[i])) ++sum;
142	if (s.contains(k2[i & absentMask])) ++sum;
143	}
144	timer.finish();
145	reallyAssert(sum == n);
146	}
147
148	static void t7(String nm, int n, NavigableSet s, Integer[] k1, Integer[] k2) {
149	int sum = 0;
150	timer.start(nm, n * 2);
151	for (int i = 0; i < n; i++) {
152	if (s.contains(k1[i])) ++sum;
153	if (s.contains(k2[i & absentMask])) ++sum;
154	}
155	timer.finish();
156	reallyAssert(sum == n);
157	}
158
159	static void t8(String nm, int n, NavigableSet s, Integer[] key, int expect) {
160	int sum = 0;
161	timer.start(nm, n);
162	for (int i = 0; i < n; i++) {
163	if (s.contains(key[i])) ++sum;
164	}
165	timer.finish();
166	reallyAssert(sum == expect);
167	}
168
169	static void higherTest(NavigableSet s) {
170	int sum = 0;
171	int iters = s.size();
172	timer.start("Higher ", iters);
173	Object e = s.first();
174	while (e != null) {
175	++sum;
176	e = s.higher(e);
177	}
178	timer.finish();
179	reallyAssert(sum == iters);
180	}
181
182	static void lowerTest(NavigableSet s) {
183	int sum = 0;
184	int iters = s.size();
185	timer.start("Lower ", iters);
186	Object e = s.first();
187	while (e != null) {
188	++sum;
189	e = s.higher(e);
190	}
191	timer.finish();
192	reallyAssert(sum == iters);
193	}
194
195	static void ceilingTest(NavigableSet s) {
196	int sum = 0;
197	int iters = s.size();
198	if (iters > absentSize) iters = absentSize;
199	timer.start("Ceiling ", iters);
200	for (int i = 0; i < iters; ++i) {
201	Object e = s.ceiling(absent[i]);
202	if (e != null)
203	++sum;
204	}
205	timer.finish();
206	reallyAssert(sum == iters);
207	}
208
209	static void floorTest(NavigableSet s) {
210	int sum = 0;
211	int iters = s.size();
212	if (iters > absentSize) iters = absentSize;
213	timer.start("Floor ", iters);
214	for (int i = 1; i < iters; ++i) {
215	Object e = s.floor(absent[i]);
216	if (e != null)
217	++sum;
218	}
219	timer.finish();
220	reallyAssert(sum == iters-1);
221	}
222
223	static void ktest(NavigableSet s, int size, Integer[] key) {
224	timer.start("Contains ", size);
225	int sum = 0;
226	for (int i = 0; i < size; i++) {
227	if (s.contains(key[i])) ++sum;
228	}
229	timer.finish();
230	reallyAssert(sum == size);
231	}
232
233	static void ittest1(NavigableSet s, int size) {
234	int sum = 0;
235	timer.start("Iter Key ", size);
236	for (Iterator it = s.iterator(); it.hasNext(); ) {
237	if (it.next() != MISSING)
238	++sum;
239	}
240	timer.finish();
241	reallyAssert(sum == size);
242	}
243
244	static void ittest(NavigableSet s, int size) {
245	ittest1(s, size);
246	}
247
248	static void rittest1(NavigableSet s, int size) {
249	int sum = 0;
250	timer.start("Desc Iter Key ", size);
251	for (Iterator it = s.descendingIterator(); it.hasNext(); ) {
252	if (it.next() != MISSING)
253	++sum;
254	}
255	timer.finish();
256	reallyAssert(sum == size);
257	}
258
259	static void rittest(NavigableSet s, int size) {
260	rittest1(s, size);
261	}
262
263	static void rtest(NavigableSet s, int size) {
264	timer.start("Remove (iterator) ", size);
265	for (Iterator it = s.iterator(); it.hasNext(); ) {
266	it.next();
267	it.remove();
268	}
269	timer.finish();
270	}
271
272	static void dtest(NavigableSet s, int size, Integer[] key) {
273	timer.start("Add (addAll) ", size * 2);
274	NavigableSet s2 = null;
275	try {
276	s2 = (NavigableSet) (s.getClass().newInstance());
277	s2.addAll(s);
278	}
279	catch (Exception e) { e.printStackTrace(); return; }
280	timer.finish();
281
282	timer.start("Iter Equals ", size * 2);
283	boolean eqt = s2.equals(s) && s.equals(s2);
284	reallyAssert(eqt);
285	timer.finish();
286
287	timer.start("Iter HashCode ", size * 2);
288	int shc = s.hashCode();
289	int s2hc = s2.hashCode();
290	reallyAssert(shc == s2hc);
291	timer.finish();
292
293	timer.start("Add (present) ", size);
294	s2.addAll(s);
295	timer.finish();
296
297	t6("Contains ", size, s2, key, absent);
298
299	boolean as2 = s2.add(absent[absentSize-1]);
300	reallyAssert(as2);
301	timer.start("Iter Equals ", size * 2);
302	eqt = s2.equals(s) && s.equals(s2);
303	if (as2)
304	reallyAssert(!eqt);
305	timer.finish();
306
307	timer.start("Iter HashCode ", size * 2);
308	int s1h = s.hashCode();
309	int s2h = s2.hashCode();
310	if (as2)
311	reallyAssert(s1h != s2h);
312	timer.finish();
313
314	timer.start("Clear ", size);
315	s.clear();
316	s2.clear();
317	timer.finish();
318	reallyAssert(s2.isEmpty() && s.isEmpty());
319	}
320
321	static void test(NavigableSet s, Integer[] key) {
322	int size = key.length;
323
324	t3("Add (absent) ", size, s, key, size);
325	t3("Add (present) ", size, s, key, 0);
326	t7("ContainsKey ", size, s, key, absent);
327	t4("ContainsKey ", size, s, key, size);
328	ktest(s, size, key);
329	t4("Contains ", absentSize, s, absent, 0);
330	t6("Contains ", size, s, key, absent);
331	t1("Contains (present) ", size, s, key, size);
332	t1("Contains (absent) ", absentSize, s, absent, 0);
333	t2("Remove (absent) ", absentSize, s, absent, 0);
334	t5("Remove (present) ", size, s, key, size / 2);
335	t3("Add (half present) ", size, s, key, size / 2);
336
337	ittest(s, size);
338	rittest(s, size);
339	higherTest(s);
340	ceilingTest(s);
341	floorTest(s);
342	lowerTest(s);
343	rtest(s, size);
344
345	t4("Contains ", size, s, key, 0);
346	t2("Remove (absent) ", size, s, key, 0);
347	t3("Add (presized) ", size, s, key, size);
348	dtest(s, size, key);
349	}
350
351	static class TestTimer {
352	private String name;
353	private long numOps;
354	private long startTime;
355	private String cname;
356
357	static final java.util.TreeMap accum = new java.util.TreeMap();
358
359	static void printStats() {
360	for (Iterator it = accum.entrySet().iterator(); it.hasNext(); ) {
361	Map.Entry e = (Map.Entry) it.next();
362	Stats stats = (Stats) e.getValue();
363	int n = stats.number;
364	double t;
365	if (n > 0)
366	t = stats.sum / n;
367	else
368	t = stats.least;
369	long nano = Math.round(1000000.0 * t);
370	System.out.println(e.getKey() + ": " + nano);
371	}
372	}
373
374	void start(String name, long numOps) {
375	this.name = name;
376	this.cname = classify();
377	this.numOps = numOps;
378	startTime = System.currentTimeMillis();
379	}
380
381	String classify() {
382	if (name.startsWith("Contains"))
383	return "Contains ";
384	else if (name.startsWith("Add"))
385	return "Add ";
386	else if (name.startsWith("Remove"))
387	return "Remove ";
388	else if (name.startsWith("Iter"))
389	return "Iter ";
390	else
391	return null;
392	}
393
394	void finish() {
395	long endTime = System.currentTimeMillis();
396	long time = endTime - startTime;
397	double timePerOp = (double) time / numOps;
398
399	Object st = accum.get(name);
400	if (st == null)
401	accum.put(name, new Stats(timePerOp));
402	else {
403	Stats stats = (Stats) st;
404	stats.sum += timePerOp;
405	stats.number++;
406	if (timePerOp < stats.least) stats.least = timePerOp;
407	}
408
409	if (cname != null) {
410	st = accum.get(cname);
411	if (st == null)
412	accum.put(cname, new Stats(timePerOp));
413	else {
414	Stats stats = (Stats) st;
415	stats.sum += timePerOp;
416	stats.number++;
417	if (timePerOp < stats.least) stats.least = timePerOp;
418	}
419	}
420
421	}
422
423	}
424
425	static class Stats {
426	double sum = 0;
427	double least;
428	int number = 0;
429	Stats(double t) { least = t; }
430	}
431
432	static Random rng = new Random();
433
434	static void shuffle(Integer[] keys) {
435	int size = keys.length;
436	for (int i = size; i > 1; i--) {
437	int r = rng.nextInt(i);
438	Integer t = keys[i-1];
439	keys[i-1] = keys[r];
440	keys[r] = t;
441	}
442	}
443
444	}